Apparatus for use in turning steerable vehicle wheels

An apparatus for use in turning steerable vehicle wheels, the apparatus comprising:

• a steering member which is axially movable relative to the vehicle to effect turning movement of the steerable vehicle wheels;
• a ball nut assembly connected with an externally threaded portion of the steering member, the steering member moving axially in response to rotation of the ball nut assembly relative to the steering member;
• a first motor connected with the ball nut assembly, the first motor being operable to effect rotation of the ball nut assembly relative to the steering member;
• and
• a second motor connected with the ball nut assembly, the second motor being operable to effect rotation of the ball nut assembly relative to the steering member.